\psset{unit=1,algebraic}
\begin{pspicture*}(-3.5,-0.5)(3.5,3.5)
\psaxes[labelFontSize=\scriptstyle,ticksize=-3pt 0,labelsep=2pt]{<->}(0,0)(-1.5,-0.5)(1.5,3.5)
\psplot[linecolor=blue]{-1}{1}{acos(x)}
\footnotesize
\rput[l](1,0.5){$f(x)=\arccos x$}
\end{pspicture*}